Environmental Law – Timeline of Key Acts

The modern era of U.S. environmental protection began in the late 1960s. Congress passed sweeping laws to protect air, water, wildlife, and public health, many of which remain the backbone of environmental law today.

National Environmental Policy Act (NEPA, 1969)

• Established a national environmental policy.
• Required federal agencies to prepare Environmental Assessments (EAs) and Environmental Impact Statements (EISs) for major actions affecting the environment.
• Created the Council on Environmental Quality (CEQ).

Clean Air Act (1970, amended 1977 & 1990)

• Authorized the EPA to regulate air emissions from stationary and mobile sources.
• Set National Ambient Air Quality Standards (NAAQS) to protect public health and welfare.
• 1990 amendments expanded controls on acid rain, ozone depletion, and toxic pollutants.

Clean Water Act (1972, amended 1977 & 1987)

• Regulated discharges of pollutants into U.S. waters.
• Established the National Pollutant Discharge Elimination System (NPDES) permit program.
• Sought to restore and maintain the integrity of the nation’s waters.

Endangered Species Act (1973)

• Provided for the conservation of threatened and endangered plants and animals.
• Protected critical habitats and prohibited harm to listed species.
• Remains one of the strongest wildlife protection laws globally.

Safe Drinking Water Act (1974, amended 1986 & 1996)

• Protected the quality of drinking water in the U.S.
• Authorized the EPA to set standards for drinking water quality and oversee states, localities, and water suppliers.

Resource Conservation and Recovery Act (RCRA, 1976)

• Gave EPA authority over the management of hazardous waste.
• Set framework for the proper disposal of solid and hazardous waste.
• Amended by the Hazardous and Solid Waste Amendments (HSWA) of 1984.

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, 1980, “Superfund”)

• Created to clean up sites contaminated with hazardous substances.
• Authorized EPA to identify responsible parties and compel clean-up or seek reimbursement.
• Funded initially by a tax on the chemical and petroleum industries.

Why It Matters Today

Together, these laws form the backbone of U.S. environmental protection. They:

Clean Air Act (CAA) (1970)

1) Link to the Text of the Act
Read the statute (42 U.S.C. § 7401 et seq.)

2) Why It Was Done
The CAA established a comprehensive federal program to regulate air emissions from stationary and mobile sources, protect public health, and improve air quality.

3) Pre-existing Law or Constitutional Rights
Built on earlier air quality statutes (1955, 1963, 1967). The 1970 Act created the modern framework for federal and state cooperation, including the establishment of the Environmental Protection Agency (EPA).

Clean Water Act (CWA) (1972)

1) Link to the Text of the Act
Read the statute (33 U.S.C. § 1251 et seq.)

2) Why It Was Done
Congress enacted the CWA to restore and maintain the chemical, physical, and biological integrity of the nation’s waters, after decades of severe pollution in rivers, lakes, and coastal areas.

3) Pre-existing Law or Constitutional Rights
The CWA reorganized and greatly expanded the Federal Water Pollution Control Act of 1948, which had been ineffective. The 1972 amendments created enforceable standards and permit systems.

Safe Drinking Water Act (SDWA, 1974)

1) Link to the Text of the Act
Read the statute (42 U.S.C. § 300f et seq.)

2) Why It Was Done
The SDWA was enacted to protect public drinking water supplies across the United States, setting national health-based standards and requiring states and water suppliers to ensure safety.

3) Pre-existing Law or Constitutional Rights
Before SDWA, drinking water safety was primarily a state and local responsibility, with no enforceable federal standards. Pollution crises and unsafe municipal supplies prompted federal action.

Resource Conservation and Recovery Act (RCRA, 1976)

1) Link to the Text of the Act
Read the statute (42 U.S.C. § 6901 et seq.)

2) Why It Was Done
RCRA was passed to address growing concerns about solid and hazardous waste disposal, ensuring safe management from “cradle to grave” and protecting human health and the environment.

3) Pre-existing Law or Constitutional Rights
Before RCRA, waste management was largely unregulated at the federal level, with states and municipalities handling disposal. Environmental disasters highlighted the need for stronger standards.

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA / Superfund, 1980)

1) Link to the Text of the Act
Read the statute (42 U.S.C. § 9601 et seq.)

2) Why It Was Done
CERCLA, known as Superfund, was enacted in response to toxic waste disasters (e.g., Love Canal). It created a federal program to identify, clean up, and hold polluters financially responsible for contaminated sites.

3) Pre-existing Law or Constitutional Rights
While RCRA (1976) regulated ongoing waste management, there was no framework to address abandoned or historic contamination. CERCLA filled that gap.

Massachusetts v. EPA (2007)

1) Link to the Actual Opinion
Read the U.S. Reports opinion (PDF)

2) Summary of the Opinion
A group of states, led by Massachusetts, sued the EPA for refusing to regulate greenhouse gases from motor vehicles under the Clean Air Act. The Supreme Court held that greenhouse gases are air pollutants under the Act and that the EPA has authority—and responsibility—to regulate them if they endanger public health or welfare.

West Virginia v. EPA (2022)

1) Link to the Actual Opinion
Read the Supreme Court opinion (PDF)

2) Summary of the Opinion
Several states challenged the EPA’s Clean Power Plan, which sought to shift electricity generation from coal to cleaner sources. The Supreme Court held 6–3 that the EPA lacked authority to implement such sweeping changes under the Clean Air Act without clear congressional authorization. The Court invoked the major questions doctrine, which requires explicit congressional approval for agencies to decide issues of vast economic and political significance.